There are numerous types of hearing problems. In the past, the solution has been to use hearing aids composed of an ear mold, that is, a piece which fits in the ear canal, a hearing aid including an amplifier speaker power supply battery regulator means to control the power and a clip for attachment to the ear and a means to connect the hearing aid to the ear mold. Generally speaking, the ear mold, that part which fits in the ear canal, is made by taking an impression of the ear in accordance with methods which are well known in the prior art, and some of which are the subject of patents in the art. The ear of a human can be considered as being composed of an outer ear, a middle ear, which has a hammer and anvil, and an inner ear. Hearing aids have been effective in solving many problems of people who have a defect in the middle ear zone. On the other hand, hearing aids have not proved to be as effective for those people having problems with the inner ear, that is, where the auditory nerves are destroyed, which some consider to be hair-like cells which are very sensitive. Person's with inner ear problems have a need for substantial power, relatively speaking, and when the power is increased, a feedback or whistling often occurs. Needless to say, this interfers with the ability of a person to hear utilizing his hearing aid.
A careful investigation demonstrates that ill-fitted ear molds are an important cause of feedback or whistling which is so objectionable. In the past, efforts have been made to position an ear mold snugly into the ear canal of a person's ear, see for example, U.S. Pat. No. 3,865,998; however, it will be readily appreciated that if the ear mold is slightly oversized and pressed into a person's ear it is to say the least quite uncomfortable. On the other hand, if it is loosened up by making it somewhat undersized, the problem of feedback is ever present when power is needed and, also, the ear mold fits loosely causing disturbing rattling noises and a general insecure feeling.
Faced with the problem of a high degree of discomfort or loose ear molds many people with inner ear problems involving destruction of the auditory nerves to a substantial degree, have been required to turn to lip reading courses and other efforts. This is because if the power is not turned up on their hearing aid, there is less amplification and words are missed and important tones and sounds involving the hearing ability are lost. When the power is increased, there is then the interfering whistling or feedback noises.